| // Copyright 2016 The Bazel Authors. All rights reserved. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| package com.google.devtools.build.android.desugar; |
| |
| import static com.google.common.base.Preconditions.checkArgument; |
| import static com.google.common.base.Preconditions.checkNotNull; |
| import static com.google.common.base.Preconditions.checkState; |
| import static com.google.devtools.build.android.desugar.LambdaClassMaker.LAMBDA_METAFACTORY_DUMPER_PROPERTY; |
| |
| import com.google.auto.value.AutoValue; |
| import com.google.common.annotations.VisibleForTesting; |
| import com.google.common.collect.ImmutableList; |
| import com.google.common.collect.ImmutableMap; |
| import com.google.common.collect.ImmutableSet; |
| import com.google.common.io.ByteStreams; |
| import com.google.common.io.Closer; |
| import com.google.devtools.build.android.Converters.ExistingPathConverter; |
| import com.google.devtools.build.android.Converters.PathConverter; |
| import com.google.devtools.build.android.desugar.CoreLibraryRewriter.UnprefixingClassWriter; |
| import com.google.devtools.common.options.Option; |
| import com.google.devtools.common.options.OptionDocumentationCategory; |
| import com.google.devtools.common.options.OptionEffectTag; |
| import com.google.devtools.common.options.OptionsBase; |
| import com.google.devtools.common.options.OptionsParser; |
| import com.google.devtools.common.options.ShellQuotedParamsFilePreProcessor; |
| import com.google.errorprone.annotations.MustBeClosed; |
| import java.io.IOError; |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.lang.reflect.Field; |
| import java.nio.file.FileSystems; |
| import java.nio.file.FileVisitResult; |
| import java.nio.file.Files; |
| import java.nio.file.Path; |
| import java.nio.file.Paths; |
| import java.nio.file.SimpleFileVisitor; |
| import java.nio.file.attribute.BasicFileAttributes; |
| import java.util.HashSet; |
| import java.util.Iterator; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Set; |
| import java.util.concurrent.atomic.AtomicInteger; |
| import javax.annotation.Nullable; |
| import org.objectweb.asm.ClassReader; |
| import org.objectweb.asm.ClassVisitor; |
| import org.objectweb.asm.ClassWriter; |
| import org.objectweb.asm.tree.ClassNode; |
| |
| /** |
| * Command-line tool to desugar Java 8 constructs that dx doesn't know what to do with, in |
| * particular lambdas and method references. |
| */ |
| class Desugar { |
| |
| /** Commandline options for {@link Desugar}. */ |
| public static class DesugarOptions extends OptionsBase { |
| @Option( |
| name = "input", |
| allowMultiple = true, |
| defaultValue = "", |
| category = "input", |
| documentationCategory = OptionDocumentationCategory.UNCATEGORIZED, |
| effectTags = {OptionEffectTag.UNKNOWN}, |
| converter = ExistingPathConverter.class, |
| abbrev = 'i', |
| help = |
| "Input Jar or directory with classes to desugar (required, the n-th input is paired with" |
| + "the n-th output)." |
| ) |
| public List<Path> inputJars; |
| |
| @Option( |
| name = "classpath_entry", |
| allowMultiple = true, |
| defaultValue = "", |
| category = "input", |
| documentationCategory = OptionDocumentationCategory.UNCATEGORIZED, |
| effectTags = {OptionEffectTag.UNKNOWN}, |
| converter = ExistingPathConverter.class, |
| help = |
| "Ordered classpath (Jar or directory) to resolve symbols in the --input Jar, like " |
| + "javac's -cp flag." |
| ) |
| public List<Path> classpath; |
| |
| @Option( |
| name = "bootclasspath_entry", |
| allowMultiple = true, |
| defaultValue = "", |
| category = "input", |
| documentationCategory = OptionDocumentationCategory.UNCATEGORIZED, |
| effectTags = {OptionEffectTag.UNKNOWN}, |
| converter = ExistingPathConverter.class, |
| help = |
| "Bootclasspath that was used to compile the --input Jar with, like javac's " |
| + "-bootclasspath flag (required)." |
| ) |
| public List<Path> bootclasspath; |
| |
| @Option( |
| name = "allow_empty_bootclasspath", |
| defaultValue = "false", |
| documentationCategory = OptionDocumentationCategory.UNDOCUMENTED, |
| effectTags = {OptionEffectTag.UNKNOWN} |
| ) |
| public boolean allowEmptyBootclasspath; |
| |
| @Option( |
| name = "only_desugar_javac9_for_lint", |
| defaultValue = "false", |
| documentationCategory = OptionDocumentationCategory.UNDOCUMENTED, |
| effectTags = {OptionEffectTag.UNKNOWN}, |
| help = |
| "A temporary flag specifically for android lint, subject to removal anytime (DO NOT USE)" |
| ) |
| public boolean onlyDesugarJavac9ForLint; |
| |
| @Option( |
| name = "rewrite_calls_to_long_compare", |
| defaultValue = "false", |
| documentationCategory = OptionDocumentationCategory.UNCATEGORIZED, |
| effectTags = {OptionEffectTag.UNKNOWN}, |
| help = |
| "Rewrite calls to Long.compare(long, long) to the JVM instruction lcmp " |
| + "regardless of --min_sdk_version.", |
| category = "misc" |
| ) |
| public boolean alwaysRewriteLongCompare; |
| |
| @Option( |
| name = "output", |
| allowMultiple = true, |
| defaultValue = "", |
| category = "output", |
| documentationCategory = OptionDocumentationCategory.UNCATEGORIZED, |
| effectTags = {OptionEffectTag.UNKNOWN}, |
| converter = PathConverter.class, |
| abbrev = 'o', |
| help = |
| "Output Jar or directory to write desugared classes into (required, the n-th output is " |
| + "paired with the n-th input, output must be a Jar if input is a Jar)." |
| ) |
| public List<Path> outputJars; |
| |
| @Option( |
| name = "verbose", |
| defaultValue = "false", |
| category = "misc", |
| documentationCategory = OptionDocumentationCategory.UNCATEGORIZED, |
| effectTags = {OptionEffectTag.UNKNOWN}, |
| abbrev = 'v', |
| help = "Enables verbose debugging output." |
| ) |
| public boolean verbose; |
| |
| @Option( |
| name = "min_sdk_version", |
| defaultValue = "1", |
| category = "misc", |
| documentationCategory = OptionDocumentationCategory.UNCATEGORIZED, |
| effectTags = {OptionEffectTag.UNKNOWN}, |
| help = "Minimum targeted sdk version. If >= 24, enables default methods in interfaces." |
| ) |
| public int minSdkVersion; |
| |
| @Option( |
| name = "emit_dependency_metadata_as_needed", |
| defaultValue = "false", |
| documentationCategory = OptionDocumentationCategory.UNCATEGORIZED, |
| effectTags = {OptionEffectTag.UNKNOWN}, |
| help = "Whether to emit META-INF/desugar_deps as needed for later consistency checking." |
| ) |
| public boolean emitDependencyMetadata; |
| |
| @Option( |
| name = "best_effort_tolerate_missing_deps", |
| defaultValue = "true", |
| category = "misc", |
| documentationCategory = OptionDocumentationCategory.UNCATEGORIZED, |
| effectTags = {OptionEffectTag.UNKNOWN}, |
| help = "Whether to tolerate missing dependencies on the classpath in some cases. You should " |
| + "strive to set this flag to false." |
| ) |
| public boolean tolerateMissingDependencies; |
| |
| @Option( |
| name = "desugar_supported_core_libs", |
| defaultValue = "false", |
| documentationCategory = OptionDocumentationCategory.UNCATEGORIZED, |
| effectTags = {OptionEffectTag.UNKNOWN}, |
| help = "Enable core library desugaring, which requires configuration with related flags." |
| ) |
| public boolean desugarCoreLibs; |
| |
| @Option( |
| name = "desugar_interface_method_bodies_if_needed", |
| defaultValue = "true", |
| category = "misc", |
| documentationCategory = OptionDocumentationCategory.UNCATEGORIZED, |
| effectTags = {OptionEffectTag.UNKNOWN}, |
| help = |
| "Rewrites default and static methods in interfaces if --min_sdk_version < 24. This " |
| + "only works correctly if subclasses of rewritten interfaces as well as uses of " |
| + "static interface methods are run through this tool as well." |
| ) |
| public boolean desugarInterfaceMethodBodiesIfNeeded; |
| |
| @Option( |
| name = "desugar_try_with_resources_if_needed", |
| defaultValue = "true", |
| category = "misc", |
| documentationCategory = OptionDocumentationCategory.UNCATEGORIZED, |
| effectTags = {OptionEffectTag.UNKNOWN}, |
| help = "Rewrites try-with-resources statements if --min_sdk_version < 19." |
| ) |
| public boolean desugarTryWithResourcesIfNeeded; |
| |
| @Option( |
| name = "desugar_try_with_resources_omit_runtime_classes", |
| defaultValue = "false", |
| category = "misc", |
| documentationCategory = OptionDocumentationCategory.UNCATEGORIZED, |
| effectTags = {OptionEffectTag.UNKNOWN}, |
| help = |
| "Omits the runtime classes necessary to support try-with-resources from the output. " |
| + "This property has effect only if --desugar_try_with_resources_if_needed is used." |
| ) |
| public boolean desugarTryWithResourcesOmitRuntimeClasses; |
| |
| @Option( |
| name = "copy_bridges_from_classpath", |
| defaultValue = "false", |
| category = "misc", |
| documentationCategory = OptionDocumentationCategory.UNCATEGORIZED, |
| effectTags = {OptionEffectTag.UNKNOWN}, |
| help = "Copy bridges from classpath to desugared classes." |
| ) |
| public boolean copyBridgesFromClasspath; |
| |
| @Option( |
| name = "core_library", |
| defaultValue = "false", |
| documentationCategory = OptionDocumentationCategory.UNDOCUMENTED, |
| effectTags = {OptionEffectTag.UNKNOWN}, |
| help = "Enables rewriting to desugar java.* classes." |
| ) |
| public boolean coreLibrary; |
| |
| /** Type prefixes that we'll move to a custom package. */ |
| @Option( |
| name = "rewrite_core_library_prefix", |
| defaultValue = "", // ignored |
| allowMultiple = true, |
| documentationCategory = OptionDocumentationCategory.UNDOCUMENTED, |
| effectTags = {OptionEffectTag.UNKNOWN}, |
| help = "Assume the given java.* prefixes are desugared." |
| ) |
| public List<String> rewriteCoreLibraryPrefixes; |
| |
| /** Interfaces whose default and static interface methods we'll emulate. */ |
| @Option( |
| name = "emulate_core_library_interface", |
| defaultValue = "", // ignored |
| allowMultiple = true, |
| documentationCategory = OptionDocumentationCategory.UNDOCUMENTED, |
| effectTags = {OptionEffectTag.UNKNOWN}, |
| help = "Assume the given java.* interfaces are emulated." |
| ) |
| public List<String> emulateCoreLibraryInterfaces; |
| |
| /** Members that we will retarget to the given new owner. */ |
| @Option( |
| name = "retarget_core_library_member", |
| defaultValue = "", // ignored |
| allowMultiple = true, |
| documentationCategory = OptionDocumentationCategory.UNDOCUMENTED, |
| effectTags = {OptionEffectTag.UNKNOWN}, |
| help = "Method invocations to retarget, given as \"class/Name#member->new/class/Name\". " |
| + "The new owner is blindly assumed to exist." |
| ) |
| public List<String> retargetCoreLibraryMembers; |
| |
| /** Set to work around b/62623509 with JaCoCo versions prior to 0.7.9. */ |
| // TODO(kmb): Remove when Android Studio doesn't need it anymore (see b/37116789) |
| @Option( |
| name = "legacy_jacoco_fix", |
| defaultValue = "false", |
| documentationCategory = OptionDocumentationCategory.UNDOCUMENTED, |
| effectTags = {OptionEffectTag.UNKNOWN}, |
| help = "Consider setting this flag if you're using JaCoCo versions prior to 0.7.9 to work " |
| + "around issues with coverage instrumentation in default and static interface methods. " |
| + "This flag may be removed when no longer needed." |
| ) |
| public boolean legacyJacocoFix; |
| } |
| |
| private final DesugarOptions options; |
| private final CoreLibraryRewriter rewriter; |
| private final LambdaClassMaker lambdas; |
| private final GeneratedClassStore store = new GeneratedClassStore(); |
| private final Set<String> visitedExceptionTypes = new HashSet<>(); |
| /** The counter to record the times of try-with-resources desugaring is invoked. */ |
| private final AtomicInteger numOfTryWithResourcesInvoked = new AtomicInteger(); |
| |
| private final boolean outputJava7; |
| private final boolean allowDefaultMethods; |
| private final boolean allowTryWithResources; |
| private final boolean allowCallsToObjectsNonNull; |
| private final boolean allowCallsToLongCompare; |
| /** An instance of Desugar is expected to be used ONLY ONCE */ |
| private boolean used; |
| |
| private Desugar(DesugarOptions options, Path dumpDirectory) { |
| this.options = options; |
| this.rewriter = new CoreLibraryRewriter(options.coreLibrary ? "__desugar__/" : ""); |
| this.lambdas = new LambdaClassMaker(dumpDirectory); |
| this.outputJava7 = options.minSdkVersion < 24; |
| this.allowDefaultMethods = |
| options.desugarInterfaceMethodBodiesIfNeeded || options.minSdkVersion >= 24; |
| this.allowTryWithResources = |
| !options.desugarTryWithResourcesIfNeeded || options.minSdkVersion >= 19; |
| this.allowCallsToObjectsNonNull = options.minSdkVersion >= 19; |
| this.allowCallsToLongCompare = options.minSdkVersion >= 19 && !options.alwaysRewriteLongCompare; |
| this.used = false; |
| } |
| |
| private void desugar() throws Exception { |
| checkState(!this.used, "This Desugar instance has been used. Please create another one."); |
| this.used = true; |
| |
| try (Closer closer = Closer.create()) { |
| IndexedInputs indexedBootclasspath = |
| new IndexedInputs(toRegisteredInputFileProvider(closer, options.bootclasspath)); |
| // Use a classloader that as much as possible uses the provided bootclasspath instead of |
| // the tool's system classloader. Unfortunately we can't do that for java. classes. |
| ClassLoader bootclassloader = |
| options.bootclasspath.isEmpty() |
| ? new ThrowingClassLoader() |
| : new HeaderClassLoader(indexedBootclasspath, rewriter, new ThrowingClassLoader()); |
| IndexedInputs indexedClasspath = |
| new IndexedInputs(toRegisteredInputFileProvider(closer, options.classpath)); |
| |
| // Process each input separately |
| for (InputOutputPair inputOutputPair : toInputOutputPairs(options)) { |
| desugarOneInput( |
| inputOutputPair, |
| indexedClasspath, |
| bootclassloader, |
| new ClassReaderFactory(indexedBootclasspath, rewriter)); |
| } |
| } |
| } |
| |
| private void desugarOneInput( |
| InputOutputPair inputOutputPair, |
| IndexedInputs indexedClasspath, |
| ClassLoader bootclassloader, |
| ClassReaderFactory bootclasspathReader) |
| throws Exception { |
| Path inputPath = inputOutputPair.getInput(); |
| Path outputPath = inputOutputPair.getOutput(); |
| checkArgument( |
| Files.isDirectory(inputPath) || !Files.isDirectory(outputPath), |
| "Input jar file requires an output jar file"); |
| |
| try (OutputFileProvider outputFileProvider = toOutputFileProvider(outputPath); |
| InputFileProvider inputFiles = toInputFileProvider(inputPath)) { |
| DependencyCollector depsCollector = createDepsCollector(); |
| IndexedInputs indexedInputFiles = new IndexedInputs(ImmutableList.of(inputFiles)); |
| // Prepend classpath with input file itself so LambdaDesugaring can load classes with |
| // lambdas. |
| IndexedInputs indexedClasspathAndInputFiles = indexedClasspath.withParent(indexedInputFiles); |
| // Note that input file and classpath need to be in the same classloader because |
| // we typically get the header Jar for inputJar on the classpath and having the header |
| // Jar in a parent loader means the header version is preferred over the real thing. |
| ClassLoader loader = |
| new HeaderClassLoader(indexedClasspathAndInputFiles, rewriter, bootclassloader); |
| |
| ClassReaderFactory classpathReader = null; |
| ClassReaderFactory bridgeMethodReader = null; |
| if (outputJava7) { |
| classpathReader = new ClassReaderFactory(indexedClasspathAndInputFiles, rewriter); |
| if (options.copyBridgesFromClasspath) { |
| bridgeMethodReader = classpathReader; |
| } else { |
| bridgeMethodReader = new ClassReaderFactory(indexedInputFiles, rewriter); |
| } |
| } |
| |
| ImmutableSet.Builder<String> interfaceLambdaMethodCollector = ImmutableSet.builder(); |
| ClassVsInterface interfaceCache = new ClassVsInterface(classpathReader); |
| CoreLibrarySupport coreLibrarySupport = |
| options.desugarCoreLibs |
| ? new CoreLibrarySupport( |
| rewriter, |
| loader, |
| options.rewriteCoreLibraryPrefixes, |
| options.emulateCoreLibraryInterfaces, |
| options.retargetCoreLibraryMembers) |
| : null; |
| |
| desugarClassesInInput( |
| inputFiles, |
| outputFileProvider, |
| loader, |
| classpathReader, |
| depsCollector, |
| bootclasspathReader, |
| coreLibrarySupport, |
| interfaceCache, |
| interfaceLambdaMethodCollector); |
| |
| desugarAndWriteDumpedLambdaClassesToOutput( |
| outputFileProvider, |
| loader, |
| classpathReader, |
| depsCollector, |
| bootclasspathReader, |
| coreLibrarySupport, |
| interfaceCache, |
| interfaceLambdaMethodCollector.build(), |
| bridgeMethodReader); |
| |
| desugarAndWriteGeneratedClasses( |
| outputFileProvider, loader, bootclasspathReader, coreLibrarySupport); |
| |
| copyThrowableExtensionClass(outputFileProvider); |
| |
| byte[] depsInfo = depsCollector.toByteArray(); |
| if (depsInfo != null) { |
| outputFileProvider.write(OutputFileProvider.DESUGAR_DEPS_FILENAME, depsInfo); |
| } |
| } |
| |
| ImmutableMap<Path, LambdaInfo> lambdasLeftBehind = lambdas.drain(); |
| checkState(lambdasLeftBehind.isEmpty(), "Didn't process %s", lambdasLeftBehind); |
| ImmutableMap<String, ClassNode> generatedLeftBehind = store.drain(); |
| checkState(generatedLeftBehind.isEmpty(), "Didn't process %s", generatedLeftBehind.keySet()); |
| } |
| |
| /** |
| * Returns a dependency collector for use with a single input Jar. If |
| * {@link DesugarOptions#emitDependencyMetadata} is set, this method instantiates the collector |
| * reflectively to allow compiling and using the desugar tool without this mechanism. |
| */ |
| private DependencyCollector createDepsCollector() { |
| if (options.emitDependencyMetadata) { |
| try { |
| return (DependencyCollector) |
| Thread.currentThread() |
| .getContextClassLoader() |
| .loadClass( |
| "com.google.devtools.build.android.desugar.dependencies.MetadataCollector") |
| .getConstructor(Boolean.TYPE) |
| .newInstance(options.tolerateMissingDependencies); |
| } catch (ReflectiveOperationException | SecurityException e) { |
| throw new IllegalStateException("Can't emit desugaring metadata as requested"); |
| } |
| } else if (options.tolerateMissingDependencies) { |
| return DependencyCollector.NoWriteCollectors.NOOP; |
| } else { |
| return DependencyCollector.NoWriteCollectors.FAIL_ON_MISSING; |
| } |
| } |
| |
| private void copyThrowableExtensionClass(OutputFileProvider outputFileProvider) { |
| if (allowTryWithResources || options.desugarTryWithResourcesOmitRuntimeClasses) { |
| // try-with-resources statements are okay in the output jar. |
| return; |
| } |
| if (this.numOfTryWithResourcesInvoked.get() <= 0) { |
| // the try-with-resources desugaring pass does nothing, so no need to copy these class files. |
| return; |
| } |
| for (String className : |
| TryWithResourcesRewriter.THROWABLE_EXT_CLASS_INTERNAL_NAMES_WITH_CLASS_EXT) { |
| try (InputStream stream = Desugar.class.getClassLoader().getResourceAsStream(className)) { |
| outputFileProvider.write(className, ByteStreams.toByteArray(stream)); |
| } catch (IOException e) { |
| throw new IOError(e); |
| } |
| } |
| } |
| |
| /** Desugar the classes that are in the inputs specified in the command line arguments. */ |
| private void desugarClassesInInput( |
| InputFileProvider inputFiles, |
| OutputFileProvider outputFileProvider, |
| ClassLoader loader, |
| @Nullable ClassReaderFactory classpathReader, |
| DependencyCollector depsCollector, |
| ClassReaderFactory bootclasspathReader, |
| @Nullable CoreLibrarySupport coreLibrarySupport, |
| ClassVsInterface interfaceCache, |
| ImmutableSet.Builder<String> interfaceLambdaMethodCollector) |
| throws IOException { |
| for (String inputFilename : inputFiles) { |
| if (OutputFileProvider.DESUGAR_DEPS_FILENAME.equals(inputFilename)) { |
| // TODO(kmb): rule out that this happens or merge input file with what's in depsCollector |
| continue; // skip as we're writing a new file like this at the end or don't want it |
| } |
| try (InputStream content = inputFiles.getInputStream(inputFilename)) { |
| // We can write classes uncompressed since they need to be converted to .dex format |
| // for Android anyways. Resources are written as they were in the input jar to avoid |
| // any danger of accidentally uncompressed resources ending up in an .apk. |
| if (inputFilename.endsWith(".class")) { |
| ClassReader reader = rewriter.reader(content); |
| UnprefixingClassWriter writer = rewriter.writer(ClassWriter.COMPUTE_MAXS); |
| ClassVisitor visitor = |
| createClassVisitorsForClassesInInputs( |
| loader, |
| classpathReader, |
| depsCollector, |
| bootclasspathReader, |
| coreLibrarySupport, |
| interfaceCache, |
| interfaceLambdaMethodCollector, |
| writer, |
| reader); |
| if (writer == visitor) { |
| // Just copy the input if there are no rewritings |
| outputFileProvider.write(inputFilename, reader.b); |
| } else { |
| reader.accept(visitor, 0); |
| String filename = writer.getClassName() + ".class"; |
| checkState( |
| (options.coreLibrary && coreLibrarySupport != null) |
| || filename.equals(inputFilename)); |
| outputFileProvider.write(filename, writer.toByteArray()); |
| } |
| } else { |
| outputFileProvider.copyFrom(inputFilename, inputFiles); |
| } |
| } |
| } |
| } |
| |
| /** |
| * Desugar the classes that are generated on the fly when we are desugaring the classes in the |
| * specified inputs. |
| */ |
| private void desugarAndWriteDumpedLambdaClassesToOutput( |
| OutputFileProvider outputFileProvider, |
| ClassLoader loader, |
| @Nullable ClassReaderFactory classpathReader, |
| DependencyCollector depsCollector, |
| ClassReaderFactory bootclasspathReader, |
| @Nullable CoreLibrarySupport coreLibrarySupport, |
| ClassVsInterface interfaceCache, |
| ImmutableSet<String> interfaceLambdaMethods, |
| @Nullable ClassReaderFactory bridgeMethodReader) |
| throws IOException { |
| checkState( |
| !allowDefaultMethods || interfaceLambdaMethods.isEmpty(), |
| "Desugaring with default methods enabled moved interface lambdas"); |
| |
| // Write out the lambda classes we generated along the way |
| ImmutableMap<Path, LambdaInfo> lambdaClasses = lambdas.drain(); |
| checkState( |
| !options.onlyDesugarJavac9ForLint || lambdaClasses.isEmpty(), |
| "There should be no lambda classes generated: %s", |
| lambdaClasses.keySet()); |
| |
| for (Map.Entry<Path, LambdaInfo> lambdaClass : lambdaClasses.entrySet()) { |
| try (InputStream bytecode = Files.newInputStream(lambdaClass.getKey())) { |
| ClassReader reader = rewriter.reader(bytecode); |
| InvokeDynamicLambdaMethodCollector collector = new InvokeDynamicLambdaMethodCollector(); |
| reader.accept(collector, ClassReader.SKIP_DEBUG | ClassReader.SKIP_FRAMES); |
| ImmutableSet<MethodInfo> lambdaMethods = collector.getLambdaMethodsUsedInInvokeDynamics(); |
| checkState(lambdaMethods.isEmpty(), |
| "Didn't expect to find lambda methods but found %s", lambdaMethods); |
| UnprefixingClassWriter writer = |
| rewriter.writer(ClassWriter.COMPUTE_MAXS /*for invoking bridges*/); |
| ClassVisitor visitor = |
| createClassVisitorsForDumpedLambdaClasses( |
| loader, |
| classpathReader, |
| depsCollector, |
| bootclasspathReader, |
| coreLibrarySupport, |
| interfaceCache, |
| interfaceLambdaMethods, |
| bridgeMethodReader, |
| lambdaClass.getValue(), |
| writer, |
| reader); |
| reader.accept(visitor, 0); |
| checkState( |
| (options.coreLibrary && coreLibrarySupport != null) |
| || rewriter |
| .unprefix(lambdaClass.getValue().desiredInternalName()) |
| .equals(writer.getClassName())); |
| outputFileProvider.write(writer.getClassName() + ".class", writer.toByteArray()); |
| } |
| } |
| } |
| |
| private void desugarAndWriteGeneratedClasses( |
| OutputFileProvider outputFileProvider, |
| ClassLoader loader, |
| ClassReaderFactory bootclasspathReader, |
| @Nullable CoreLibrarySupport coreLibrarySupport) |
| throws IOException { |
| // Write out any classes we generated along the way |
| ImmutableMap<String, ClassNode> generatedClasses = store.drain(); |
| checkState( |
| generatedClasses.isEmpty() || (allowDefaultMethods && outputJava7), |
| "Didn't expect generated classes but got %s", |
| generatedClasses.keySet()); |
| for (Map.Entry<String, ClassNode> generated : generatedClasses.entrySet()) { |
| UnprefixingClassWriter writer = rewriter.writer(ClassWriter.COMPUTE_MAXS); |
| // checkState above implies that we want Java 7 .class files, so send through that visitor. |
| // Don't need a ClassReaderFactory b/c static interface methods should've been moved. |
| ClassVisitor visitor = writer; |
| if (coreLibrarySupport != null) { |
| visitor = new EmulatedInterfaceRewriter(visitor, coreLibrarySupport); |
| visitor = new CorePackageRenamer(visitor, coreLibrarySupport); |
| visitor = new CoreLibraryInvocationRewriter(visitor, coreLibrarySupport); |
| } |
| |
| if (!allowTryWithResources) { |
| CloseResourceMethodScanner closeResourceMethodScanner = new CloseResourceMethodScanner(); |
| generated.getValue().accept(closeResourceMethodScanner); |
| visitor = |
| new TryWithResourcesRewriter( |
| visitor, |
| loader, |
| visitedExceptionTypes, |
| numOfTryWithResourcesInvoked, |
| closeResourceMethodScanner.hasCloseResourceMethod()); |
| } |
| if (!allowCallsToObjectsNonNull) { |
| // Not sure whether there will be implicit null check emitted by javac, so we rerun |
| // the inliner again |
| visitor = new ObjectsRequireNonNullMethodRewriter(visitor, rewriter); |
| } |
| if (!allowCallsToLongCompare) { |
| visitor = new LongCompareMethodRewriter(visitor, rewriter); |
| } |
| |
| visitor = new Java7Compatibility(visitor, (ClassReaderFactory) null, bootclasspathReader); |
| generated.getValue().accept(visitor); |
| checkState( |
| (options.coreLibrary && coreLibrarySupport != null) |
| || rewriter.unprefix(generated.getKey()).equals(writer.getClassName())); |
| outputFileProvider.write(writer.getClassName() + ".class", writer.toByteArray()); |
| } |
| } |
| |
| /** |
| * Create the class visitors for the lambda classes that are generated on the fly. If no new class |
| * visitors are not generated, then the passed-in {@code writer} will be returned. |
| */ |
| private ClassVisitor createClassVisitorsForDumpedLambdaClasses( |
| ClassLoader loader, |
| @Nullable ClassReaderFactory classpathReader, |
| DependencyCollector depsCollector, |
| ClassReaderFactory bootclasspathReader, |
| @Nullable CoreLibrarySupport coreLibrarySupport, |
| ClassVsInterface interfaceCache, |
| ImmutableSet<String> interfaceLambdaMethods, |
| @Nullable ClassReaderFactory bridgeMethodReader, |
| LambdaInfo lambdaClass, |
| UnprefixingClassWriter writer, |
| ClassReader input) { |
| ClassVisitor visitor = checkNotNull(writer); |
| |
| if (coreLibrarySupport != null) { |
| visitor = new EmulatedInterfaceRewriter(visitor, coreLibrarySupport); |
| visitor = new CorePackageRenamer(visitor, coreLibrarySupport); |
| visitor = new CoreLibraryInvocationRewriter(visitor, coreLibrarySupport); |
| } |
| |
| if (!allowTryWithResources) { |
| CloseResourceMethodScanner closeResourceMethodScanner = new CloseResourceMethodScanner(); |
| input.accept(closeResourceMethodScanner, ClassReader.SKIP_DEBUG); |
| visitor = |
| new TryWithResourcesRewriter( |
| visitor, |
| loader, |
| visitedExceptionTypes, |
| numOfTryWithResourcesInvoked, |
| closeResourceMethodScanner.hasCloseResourceMethod()); |
| } |
| if (!allowCallsToObjectsNonNull) { |
| // Not sure whether there will be implicit null check emitted by javac, so we rerun |
| // the inliner again |
| visitor = new ObjectsRequireNonNullMethodRewriter(visitor, rewriter); |
| } |
| if (!allowCallsToLongCompare) { |
| visitor = new LongCompareMethodRewriter(visitor, rewriter); |
| } |
| if (outputJava7) { |
| // null ClassReaderFactory b/c we don't expect to need it for lambda classes |
| visitor = new Java7Compatibility(visitor, (ClassReaderFactory) null, bootclasspathReader); |
| if (options.desugarInterfaceMethodBodiesIfNeeded) { |
| visitor = |
| new DefaultMethodClassFixer( |
| visitor, |
| classpathReader, |
| depsCollector, |
| coreLibrarySupport, |
| bootclasspathReader, |
| loader); |
| visitor = |
| new InterfaceDesugaring( |
| visitor, |
| interfaceCache, |
| depsCollector, |
| bootclasspathReader, |
| loader, |
| store, |
| options.legacyJacocoFix); |
| } |
| } |
| |
| visitor = |
| new LambdaClassFixer( |
| visitor, |
| lambdaClass, |
| bridgeMethodReader, |
| loader, |
| interfaceLambdaMethods, |
| allowDefaultMethods, |
| outputJava7); |
| // Send lambda classes through desugaring to make sure there's no invokedynamic |
| // instructions in generated lambda classes (checkState below will fail) |
| visitor = |
| new LambdaDesugaring( |
| visitor, loader, lambdas, null, ImmutableSet.of(), allowDefaultMethods); |
| return visitor; |
| } |
| |
| /** |
| * Create the class visitors for the classes which are in the inputs. If new visitors are created, |
| * then all these visitors and the passed-in writer will be chained together. If no new visitor is |
| * created, then the passed-in {@code writer} will be returned. |
| */ |
| private ClassVisitor createClassVisitorsForClassesInInputs( |
| ClassLoader loader, |
| @Nullable ClassReaderFactory classpathReader, |
| DependencyCollector depsCollector, |
| ClassReaderFactory bootclasspathReader, |
| @Nullable CoreLibrarySupport coreLibrarySupport, |
| ClassVsInterface interfaceCache, |
| ImmutableSet.Builder<String> interfaceLambdaMethodCollector, |
| UnprefixingClassWriter writer, |
| ClassReader input) { |
| ClassVisitor visitor = checkNotNull(writer); |
| |
| if (coreLibrarySupport != null) { |
| visitor = new EmulatedInterfaceRewriter(visitor, coreLibrarySupport); |
| visitor = new CorePackageRenamer(visitor, coreLibrarySupport); |
| visitor = new CoreLibraryInvocationRewriter(visitor, coreLibrarySupport); |
| } |
| |
| if (!allowTryWithResources) { |
| CloseResourceMethodScanner closeResourceMethodScanner = new CloseResourceMethodScanner(); |
| input.accept(closeResourceMethodScanner, ClassReader.SKIP_DEBUG); |
| visitor = |
| new TryWithResourcesRewriter( |
| visitor, |
| loader, |
| visitedExceptionTypes, |
| numOfTryWithResourcesInvoked, |
| closeResourceMethodScanner.hasCloseResourceMethod()); |
| } |
| if (!allowCallsToObjectsNonNull) { |
| visitor = new ObjectsRequireNonNullMethodRewriter(visitor, rewriter); |
| } |
| if (!allowCallsToLongCompare) { |
| visitor = new LongCompareMethodRewriter(visitor, rewriter); |
| } |
| if (!options.onlyDesugarJavac9ForLint) { |
| if (outputJava7) { |
| visitor = new Java7Compatibility(visitor, classpathReader, bootclasspathReader); |
| if (options.desugarInterfaceMethodBodiesIfNeeded) { |
| visitor = |
| new DefaultMethodClassFixer( |
| visitor, |
| classpathReader, |
| depsCollector, |
| coreLibrarySupport, |
| bootclasspathReader, |
| loader); |
| visitor = |
| new InterfaceDesugaring( |
| visitor, |
| interfaceCache, |
| depsCollector, |
| bootclasspathReader, |
| loader, |
| store, |
| options.legacyJacocoFix); |
| } |
| } |
| |
| // LambdaDesugaring is relatively expensive, so check first whether we need it. Additionally, |
| // we need to collect lambda methods referenced by invokedynamic instructions up-front anyway. |
| // TODO(kmb): Scan constant pool instead of visiting the class to find bootstrap methods etc. |
| InvokeDynamicLambdaMethodCollector collector = new InvokeDynamicLambdaMethodCollector(); |
| input.accept(collector, ClassReader.SKIP_DEBUG | ClassReader.SKIP_FRAMES); |
| ImmutableSet<MethodInfo> methodsUsedInInvokeDynamics = |
| collector.getLambdaMethodsUsedInInvokeDynamics(); |
| if (!methodsUsedInInvokeDynamics.isEmpty() || collector.needOuterClassRewrite()) { |
| visitor = |
| new LambdaDesugaring( |
| visitor, |
| loader, |
| lambdas, |
| interfaceLambdaMethodCollector, |
| methodsUsedInInvokeDynamics, |
| allowDefaultMethods); |
| } |
| } |
| return visitor; |
| } |
| |
| public static void main(String[] args) throws Exception { |
| // It is important that this method is called first. See its javadoc. |
| Path dumpDirectory = createAndRegisterLambdaDumpDirectory(); |
| verifyLambdaDumpDirectoryRegistered(dumpDirectory); |
| |
| DesugarOptions options = parseCommandLineOptions(args); |
| if (options.verbose) { |
| System.out.printf("Lambda classes will be written under %s%n", dumpDirectory); |
| } |
| new Desugar(options, dumpDirectory).desugar(); |
| } |
| |
| static void verifyLambdaDumpDirectoryRegistered(Path dumpDirectory) throws IOException { |
| try { |
| Class<?> klass = Class.forName("java.lang.invoke.InnerClassLambdaMetafactory"); |
| Field dumperField = klass.getDeclaredField("dumper"); |
| dumperField.setAccessible(true); |
| Object dumperValue = dumperField.get(null); |
| checkNotNull(dumperValue, "Failed to register lambda dump directory '%s'", dumpDirectory); |
| |
| Field dumperPathField = dumperValue.getClass().getDeclaredField("dumpDir"); |
| dumperPathField.setAccessible(true); |
| Object dumperPath = dumperPathField.get(dumperValue); |
| checkState( |
| dumperPath instanceof Path && Files.isSameFile(dumpDirectory, (Path) dumperPath), |
| "Inconsistent lambda dump directories. real='%s', expected='%s'", |
| dumperPath, |
| dumpDirectory); |
| } catch (ReflectiveOperationException e) { |
| // We do not want to crash Desugar, if we cannot load or access these classes or fields. |
| // We aim to provide better diagnostics. If we cannot, just let it go. |
| e.printStackTrace(System.err); // To silence error-prone's complaint. |
| } |
| } |
| |
| /** |
| * LambdaClassMaker generates lambda classes for us, but it does so by essentially simulating the |
| * call to LambdaMetafactory that the JVM would make when encountering an invokedynamic. |
| * LambdaMetafactory is in the JDK and its implementation has a property to write out ("dump") |
| * generated classes, which we take advantage of here. This property can be set externally, and in |
| * that case the specified directory is used as a temporary dir. Otherwise, it will be set here, |
| * before doing anything else since the property is read in the static initializer. |
| */ |
| static Path createAndRegisterLambdaDumpDirectory() throws IOException { |
| String propertyValue = System.getProperty(LAMBDA_METAFACTORY_DUMPER_PROPERTY); |
| if (propertyValue != null) { |
| Path path = Paths.get(propertyValue); |
| checkState(Files.isDirectory(path), "The path '%s' is not a directory.", path); |
| // It is not necessary to check whether 'path' is an empty directory. It is possible that |
| // LambdaMetafactory is loaded before this class, and there are already lambda classes dumped |
| // into the 'path' folder. |
| // TODO(kmb): Maybe we can empty the folder here. |
| return path; |
| } |
| |
| Path dumpDirectory = Files.createTempDirectory("lambdas"); |
| System.setProperty(LAMBDA_METAFACTORY_DUMPER_PROPERTY, dumpDirectory.toString()); |
| deleteTreeOnExit(dumpDirectory); |
| return dumpDirectory; |
| } |
| |
| private static DesugarOptions parseCommandLineOptions(String[] args) { |
| OptionsParser parser = OptionsParser.newOptionsParser(DesugarOptions.class); |
| parser.setAllowResidue(false); |
| parser.enableParamsFileSupport(new ShellQuotedParamsFilePreProcessor(FileSystems.getDefault())); |
| parser.parseAndExitUponError(args); |
| DesugarOptions options = parser.getOptions(DesugarOptions.class); |
| |
| checkArgument(!options.inputJars.isEmpty(), "--input is required"); |
| checkArgument( |
| options.inputJars.size() == options.outputJars.size(), |
| "Desugar requires the same number of inputs and outputs to pair them. #input=%s,#output=%s", |
| options.inputJars.size(), |
| options.outputJars.size()); |
| checkArgument( |
| !options.bootclasspath.isEmpty() || options.allowEmptyBootclasspath, |
| "At least one --bootclasspath_entry is required"); |
| for (Path path : options.bootclasspath) { |
| checkArgument(!Files.isDirectory(path), "Bootclasspath entry must be a jar file: %s", path); |
| } |
| checkArgument(!options.desugarCoreLibs |
| || !options.rewriteCoreLibraryPrefixes.isEmpty() |
| || !options.emulateCoreLibraryInterfaces.isEmpty(), |
| "--desugar_supported_core_libs requires specifying renamed and/or emulated core libraries"); |
| return options; |
| } |
| |
| private static ImmutableList<InputOutputPair> toInputOutputPairs(DesugarOptions options) { |
| final ImmutableList.Builder<InputOutputPair> ioPairListbuilder = ImmutableList.builder(); |
| for (Iterator<Path> inputIt = options.inputJars.iterator(), |
| outputIt = options.outputJars.iterator(); |
| inputIt.hasNext(); ) { |
| ioPairListbuilder.add(InputOutputPair.create(inputIt.next(), outputIt.next())); |
| } |
| return ioPairListbuilder.build(); |
| } |
| |
| @VisibleForTesting |
| static class ThrowingClassLoader extends ClassLoader { |
| @Override |
| protected Class<?> loadClass(String name, boolean resolve) throws ClassNotFoundException { |
| if (name.startsWith("java.")) { |
| // Use system class loader for java. classes, since ClassLoader.defineClass gets |
| // grumpy when those don't come from the standard place. |
| return super.loadClass(name, resolve); |
| } |
| throw new ClassNotFoundException(); |
| } |
| } |
| |
| private static void deleteTreeOnExit(final Path directory) { |
| Thread shutdownHook = |
| new Thread() { |
| @Override |
| public void run() { |
| try { |
| deleteTree(directory); |
| } catch (IOException e) { |
| throw new RuntimeException("Failed to delete " + directory, e); |
| } |
| } |
| }; |
| Runtime.getRuntime().addShutdownHook(shutdownHook); |
| } |
| |
| /** Recursively delete a directory. */ |
| private static void deleteTree(final Path directory) throws IOException { |
| if (directory.toFile().exists()) { |
| Files.walkFileTree( |
| directory, |
| new SimpleFileVisitor<Path>() { |
| @Override |
| public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) |
| throws IOException { |
| Files.delete(file); |
| return FileVisitResult.CONTINUE; |
| } |
| |
| @Override |
| public FileVisitResult postVisitDirectory(Path dir, IOException exc) |
| throws IOException { |
| Files.delete(dir); |
| return FileVisitResult.CONTINUE; |
| } |
| }); |
| } |
| } |
| |
| /** Transform a Path to an {@link OutputFileProvider} */ |
| @MustBeClosed |
| private static OutputFileProvider toOutputFileProvider(Path path) throws IOException { |
| if (Files.isDirectory(path)) { |
| return new DirectoryOutputFileProvider(path); |
| } else { |
| return new ZipOutputFileProvider(path); |
| } |
| } |
| |
| /** Transform a Path to an InputFileProvider that needs to be closed by the caller. */ |
| @MustBeClosed |
| private static InputFileProvider toInputFileProvider(Path path) throws IOException { |
| if (Files.isDirectory(path)) { |
| return new DirectoryInputFileProvider(path); |
| } else { |
| return new ZipInputFileProvider(path); |
| } |
| } |
| |
| /** |
| * Transform a list of Path to a list of InputFileProvider and register them with the given |
| * closer. |
| */ |
| @SuppressWarnings("MustBeClosedChecker") |
| @VisibleForTesting |
| static ImmutableList<InputFileProvider> toRegisteredInputFileProvider( |
| Closer closer, List<Path> paths) throws IOException { |
| ImmutableList.Builder<InputFileProvider> builder = new ImmutableList.Builder<>(); |
| for (Path path : paths) { |
| builder.add(closer.register(toInputFileProvider(path))); |
| } |
| return builder.build(); |
| } |
| |
| /** Pair input and output. */ |
| @AutoValue |
| abstract static class InputOutputPair { |
| |
| static InputOutputPair create(Path input, Path output) { |
| return new AutoValue_Desugar_InputOutputPair(input, output); |
| } |
| |
| abstract Path getInput(); |
| |
| abstract Path getOutput(); |
| } |
| } |